Everyday tools that run in your browser
487 small tools for converting, formatting, generating, editing images, calculating and more. 486 of them never send your input anywhere, so pasting a real token or key is fine. The other one needs a network request and is marked server.
Or browse the full list- tools, all free
- 487
- tools, all free
- no account, no sign-up
- run entirely in your browser
- 486
- run entirely in your browser
- input never leaves the tab
- categories
- 18
- categories
- in 8 sections
- finds any tool
- ⌘K
- finds any tool
- from every page
Explore by section
8 sections, each split into categories and small groups, so you can find a tool by the job you are doing.
JSON & data
59 toolsFormat, query, patch and validate JSON, YAML, XML and CSV, and turn a sample payload into typed code.
Start with
JSON PrettifyRe-indent JSON with consistent spacing so it is easy to scan.JSONPath TesterRun RFC 9535 JSONPath queries against a JSON document and see the matched values, their normalized paths, and where they sit.JSON to TypeScriptTurn a JSON sample into TypeScript interfaces or types, with nested objects named and optional keys worked out from arrays.Encode & convert
56 toolsBase64 to Base85, number bases and floats, timestamps and time zones, and every unit you are likely to meet.
Start with
Base64 Encoder / DecoderConvert text to Base64 and back, with UTF-8 support and an optional URL-safe alphabet.Timestamp ConverterTurn Unix seconds, milliseconds, ISO 8601 or RFC 2822 dates into every common format, in your zone or any other.Length ConverterTurn a distance in metres, feet, miles, nautical miles or light-years into every other length unit at once.Text & writing
35 toolsDiff, clean, count and restyle text: find duplicate lines, rewrap paragraphs, mask secrets in logs, read it aloud.
Start with
Text DiffCompare two blocks of text and highlight what changed — by line, by word, or by character.Whitespace & Unicode CleanerStrip invisible characters, collapse spaces, trim lines, normalise Unicode, straighten quotes and remove accents, with a count of every change.Word FrequencyCount how often each word or phrase appears in a text, with stop-word filtering, n-grams and CSV export.Web & design
66 toolsParse and build URLs, write CSP and security headers, convert Markdown, and pick colours, gradients and shadows.
Start with
URL ParserBreak a URL into its parts: scheme, host, port, path, query parameters, and credentials.CSP GeneratorBuild a Content-Security-Policy directive by directive, or paste one to see what it allows and where it is weak.Color Palette GeneratorTurn one colour into harmonies and a 50–950 OKLCH tint and shade scale, exported as CSS variables or Tailwind config.Dev & ops
85 toolsRegex, SQL and Git helpers, Docker and Kubernetes generators, nginx and systemd config, firewalls and subnets.
Start with
Regex TesterTry a regular expression against sample text and watch every match and capture group highlight as you type.Docker Run → ComposePaste a docker run command and get the equivalent docker-compose service definition.IPv4 Subnet CalculatorBreak an IPv4 CIDR block down into its network and broadcast address, usable host range, mask, and size.Security
41 toolsHashes, HMACs, keys and certificates, passwords and JWTs, computed in your browser so secrets stay on your machine.
Start with
Hash TextRun text through MD5, SHA-1, SHA-256, SHA-3 and other digests, with each result shown in several encodings at once.JWT ParserSplit a JSON Web Token into its header, payload, and signature and read the decoded claims.Certificate DecoderDecode a PEM certificate or CSR to see its subject, issuer, validity, names, key and fingerprints.Generate & media
43 toolsUUIDs and other IDs, seeded mock data, QR codes and barcodes, and image tools that never upload a file.
Start with
UUID GeneratorCreate RFC 4122 UUIDs (v1, v3, v4, v5) singly or in bulk, in several output formats.QR Code GeneratorTurn a URL or any text into a QR code, set the error-correction level, and download it.Image ResizerScale images by percentage or to exact pixels, with contain, cover-crop or stretch fitting and sharp step-down downscaling, all without leaving your browser.Calculators & reference
102 toolsDate maths, electronics, money and infrastructure calculators, a Discord toolkit, and searchable cheatsheets.
Start with
Date Difference CalculatorCount the years, months, days and business days between two dates, with totals down to the second.Ohm's Law CalculatorEnter any two of voltage, current, resistance and power to get the other two, with SI prefixes like 4.7k and 20m.Git CheatsheetA searchable quick reference for Git — everyday commands, branching, undoing mistakes, stashing, remotes, and history search.One input, five tools
Edit the text. Each row is computed in this tab by the same logic the tool uses; open a row to get the full tool with its options.
| Tool | Output |
|---|---|
| URL Encoder / Decoder | Hello%20%3CPrismKit%3E%20%26%20internationalization |
| Hash Text (SHA-256) | |
| Slugify String | hello-prismkit-internationalization |
| HTML Entities Escaper | Hello <PrismKit> & internationalization |
| Numeronym Generator | H3o <P6t> & i18n |
Checked against the standards
A converter you can't trust is worse than none. The logic behind the tools is tested on its own, and where a standard publishes test vectors, the tool has to reproduce them exactly.
- Base32 · Base58 · Ascii85RFC 4648 and Z85 spec vectors, Bitcoin genesis address
- PBKDF2 & HKDFRFC 6070 and RFC 5869 test cases
- JWT signingRFC 7515 Appendix A.1 token
- WPA-PSKIEEE 802.11i test vectors
- Semver rangesnode-semver's own satisfies / bump cases
- JSON Patch & Merge PatchRFC 6902 and RFC 7396 appendix examples
- JSONPathRFC 9535 bookstore queries
- IEEE 754 floatsreference encodings for half, single and double
- PunycodeRFC 3492 sample, cross-checked with the URL parser
How every tool works
Private by default
Tools compute in this tab, so pasting a real token, key or log is fine. The one tool that needs a network request is marked server.
Live as you type
No Convert buttons. Output updates on every keystroke, every value has a copy button, and each tool opens on a working example.
Keyboard-first
⌘K jumps to any tool from any page, / filters a cheatsheet, and ⌘↵ runs the main action where a tool has one.
Made to share
Every tool has a stable link and a Markdown copy of its page, ready for a ticket, a README or an LLM prompt.
All 487 tools
JSON & data
59 toolsFormat, query, patch and validate JSON, YAML, XML and CSV, and turn a sample payload into typed code.
JSON
36— Prettify, query, patch, validate, and convert JSON, and generate code from itView & format
Re-indent JSON with consistent spacing so it is easy to scan.
Strip whitespace and line breaks from JSON to produce the smallest valid output.
Explore JSON as a collapsible tree and click any node to copy its path.
Sort JSON object keys recursively in ascending or descending order.
Escape text into a JSON string literal, unescape it back, or stringify JSON inside a string.
Edit JSON as a tree or as text, kept in sync, with undo, redo and validation.
Transform
Flatten nested JSON into dot and bracket paths, or unflatten it back.
Apply an RFC 6902 JSON Patch to a document, or generate the patch that turns one document into another.
Apply or generate an RFC 7396 merge patch, or deep-merge several JSON documents with a choice of array strategy.
Compare two JSON documents and see added, removed, and changed values highlighted side by side.
Validate & query
Validate a JSON document against a JSON Schema (draft 2020-12 core keywords) and list every error with its instance and schema path.
Infer a draft 2020-12 JSON Schema from a JSON sample, including required keys and common string formats.
Run RFC 9535 JSONPath queries against a JSON document and see the matched values, their normalized paths, and where they sit.
See where the bytes in a JSON document go: size by path and key, depth, type counts, the largest arrays and strings, and repeated values.
Strictly lint JSON for duplicate keys, trailing commas, comments, NaN, big integers and other problems, with line and column for each and a one-click fix.
Run JMESPath queries against JSON and see the result live.
Convert
Flatten an array of JSON objects into CSV, working out the column headers for you.
Convert JSON to XML with attributes, text nodes, and repeated elements for arrays.
Turn JSON into clean, readable YAML with your choice of indentation.
Convert a JSON object into a TOML config file, with a clear message when something has no TOML equivalent.
Turn a JSON array or CSV into a CREATE TABLE with inferred column types and batched INSERT statements for PostgreSQL, MySQL, SQLite or SQL Server.
Turn a nested JSON config into .env lines with UPPER_SNAKE keys and minimal quoting, or read a .env file back into JSON.
Convert JSON to a PHP array literal in short or array() syntax, or parse a PHP array back into JSON.
Convert a JavaScript or JSON5 object literal with comments, single quotes and unquoted keys into strict JSON, and back, without running any code.
Encode JSON as MessagePack bytes in hex or Base64, or decode a .msgpack file back into JSON.
Convert JSON to TOON, the compact Token-Oriented Object Notation for LLM prompts, and back, with a size comparison.
Convert JSON to CSV, TSV, YAML, XML, Markdown or HTML tables and SQL INSERT statements, flattening nested objects.
Generate code
Turn a JSON sample into TypeScript interfaces or types, with nested objects named and optional keys worked out from arrays.
Turn a JSON sample into Zod or Valibot schemas with optional and nullable fields, string format checks and inferred types.
Turn a JSON sample into Go structs with json tags, int64 and float64 detection, and pointers or omitempty for optional keys.
Turn a JSON sample into Python dataclasses, Pydantic models or TypedDicts, with aliases for keys that are not valid identifiers.
Turn a JSON sample into Rust structs with serde derives, renames, Option and Vec fields.
Turn a JSON sample into Java records, Kotlin data classes or C# records with the right JSON name annotations.
Generate PHP 8 classes with typed, readonly constructor-promoted properties and a fromArray factory from a JSON sample.
Generate proto3 message definitions from a JSON sample, with repeated fields, int32 or int64 picked from the data, and json_name options.
Write JSON or HTML in a short indentation-based shorthand and get the full output.
Data Formats
23— YAML, XML, CSV, TOML, .env, and .properties: format, validate, and convertYAML
Re-dump a YAML document with consistent indentation, optionally sorting the keys.
Deep-merge two or more YAML documents, with each one overriding the values before it.
Flatten nested YAML into dotted keys, or expand dotted keys back into nested structure.
Convert YAML into JSON, including multi-document streams.
Convert a YAML mapping into equivalent TOML.
XML
Re-indent an XML document with consistent spacing and line breaks.
Check whether an XML document is well-formed and point to the first place parsing fails.
Convert an XML document into JSON, keeping attributes as @-prefixed keys.
Render an XML document as a nested HTML table and copy the generated markup.
Evaluate an XPath expression against an XML document and inspect the nodes it selects.
Apply an XSLT stylesheet to an XML document and see the transformed result.
CSV
Open a CSV or TSV file as a sortable, filterable table with per-column stats, all in your browser.
Trim cells, drop empty rows and columns, remove duplicates, fix ragged rows and change the delimiter or quoting of a CSV file.
Parse CSV or TSV into JSON objects or arrays, with delimiter detection and optional type conversion.
Turn CSV into a Markdown, HTML, LaTeX, ASCII or MediaWiki table with per-column alignment.
Split a CSV into files of N rows or by a column's value, or merge several CSVs by matching header names.
Convert MySQL or PostgreSQL INSERT INTO statements into CSV or JSON rows.
TOML, .env & properties
Parse TOML into JSON, with dates written as ISO 8601 strings.
Convert TOML into YAML, with dates written as ISO 8601 strings.
Turn environment variables from a .env file into JSON, YAML, shell exports, docker run flags, Compose or Kubernetes env lists, and back.
Convert Java .properties files to JSON or YAML and back, with nested keys and unicode escapes.
Validate TOML and list every duplicate key, table conflict and redefinition, with a normalised re-emit.
Encode & convert
56 toolsBase64 to Base85, number bases and floats, timestamps and time zones, and every unit you are likely to meet.
Encoding
22— Base64, Base32/58/85, hex, binary, escaping, punycode, and MorseBase-N
Convert text to Base64 and back, with UTF-8 support and an optional URL-safe alphabet.
Turn any file into Base64 or a data URL, or rebuild a downloadable file from Base64, all inside your browser.
Encode and decode Base32, Base32hex, Crockford Base32 and z-base-32 from text or hex bytes.
Encode and decode Base58 with the Bitcoin, Flickr or Ripple alphabet, and create or verify Base58Check strings.
Encode and decode Adobe Ascii85 and ZeroMQ Z85 from text or hex bytes.
Encode and decode uuencode and xxencode, with begin and end file framing.
Convert hex byte lists to Base64 or Base64URL and back, and generate byte-array literals for C, JS, Python, Go, Rust and Java.
Text ↔ bytes
Turn text into UTF-8 bytes written as 8-bit binary, or read binary back as text.
Show the UTF-8 bytes of any text in hexadecimal with your choice of separator, and decode hex back to text.
List the code points of any text as U+, JavaScript, HTML, CSS and Python escapes, and decode any of them back.
Break text into characters with their code points, UTF-8 bytes and UTF-16 units, and spot invisible, bidi and lookalike characters.
Guess the character encoding of a file or byte dump, preview every decoding, and repair UTF-8 mojibake.
Escaping
Escape or unescape text for JSON, JavaScript, HTML, XML, SQL, regex, shell, URLs, CSV and C/Java strings.
Convert reserved characters like <, >, and & into HTML entities, or turn entities back into characters.
Encode and decode Quoted-Printable email bodies and RFC 2047 encoded-word headers.
Convert internationalized domain names between Unicode and their ASCII xn-- form.
Escape text to Java \uXXXX, Python, JavaScript, CSS or HTML numeric escapes and back, with surrogate pairs for emoji.
Signals
Files
Identify any file from its magic bytes and see whether its extension or reported MIME type is lying.
Compress or decompress text and files with gzip, zlib deflate or raw deflate, with sizes and ratio.
View any file as an xxd-style hex dump, or turn a pasted hex dump back into a binary file.
Units
23— Length, mass, temperature, data sizes, CSS units, and every other unitPhysical
Turn a distance in metres, feet, miles, nautical miles or light-years into every other length unit at once.
Convert between grams, kilograms, tonnes, ounces, pounds, stones and tons using the exact pound definition.
Switch a temperature between Celsius, Fahrenheit, Kelvin and Rankine, negative values included.
See one area in square metres, hectares, acres, square feet, square miles and more.
Convert litres and cubic units to US and imperial gallons, pints, cups and spoons side by side.
Express a speed in km/h, mph, m/s, ft/s, knots or as a fraction of the speed of light.
Break a duration down into nanoseconds through years, using average Gregorian months and years.
Convert pascals, bar, atmospheres, psi, torr and inches of mercury in one view.
Move between joules, calories, watt-hours, BTU, electronvolts and foot-pounds.
Compare watts, kilowatts, mechanical and metric horsepower, and BTU per hour.
Convert newtons, kilonewtons, dynes, kilogram-force, pound-force, kips and poundals.
Convert metres per second squared, g-force, gal, feet per second squared and speed-gain units.
Convert an angle between degrees, radians, gradians, arcminutes, arcseconds and turns.
Convert hertz up to terahertz, plus revolutions per minute and radians per second.
Convert lux, foot-candles, phots, nox, and lumens per area.
Convert cubic metres per second, litres per minute, CFM, gallons per minute, and barrels per day.
Convert kilocalories, nutrition-label Calories, and kilojoules.
Digital
Converters
11— Number bases, floats, timestamps, time zones, case, and coordinatesNumbers
Convert whole numbers of any size between binary, octal, decimal, hexadecimal and any base up to 36.
Convert decimals to IEEE 754 half, single and double precision bits and back, with the exact stored value and rounding error.
Swap integers and hex bytes between big-endian, little-endian and PDP-11 middle-endian byte orders.
Convert numbers from 1 to 3999 into Roman numerals and check that a numeral is written in standard form.
Convert amounts to and from Chinese financial uppercase (大写金额) for cheques and invoices.
Time
Text & writing
35 toolsDiff, clean, count and restyle text: find duplicate lines, rewrap paragraphs, mask secrets in logs, read it aloud.
Text
35— Compare, clean up, analyse, style, and read textCompare
Compare two blocks of text and highlight what changed — by line, by word, or by character.
Compare two Markdown documents block by block and word by word, rendered side by side or as a unified diff.
Compare two lists to see what is only in one, in both, or in either.
Compare two strings with Levenshtein, Damerau, Jaro-Winkler and Hamming distances, and see the character edits between them.
Clean up
Strip invisible characters, collapse spaces, trim lines, normalise Unicode, straighten quotes and remove accents, with a count of every change.
Reveal tabs, spaces, no-break and zero-width characters, line endings and trailing whitespace, then copy a cleaned version.
Convert tabs and spaces, re-indent code, trim trailing whitespace and normalise line endings.
Turn straight quotes into curly English, German, French or Japanese quotes, or back again, with apostrophes, primes, dashes and ellipses handled.
Search text by plain string or regex and replace every match, with capture groups and a live highlighted preview.
Find and mask emails, IP addresses, card numbers, tokens, keys and phone numbers in logs or any pasted text.
Turn HTML into readable plain text with line breaks, list markers and optional link URLs.
Fix text typed with the wrong keyboard layout, between QWERTY, AZERTY, QWERTZ, Dvorak, Colemak, Russian and Hebrew.
Lines & lists
Clean up, dedupe, sort and reformat a list — add quotes, prefixes and join it with any separator.
Find repeated lines in a list or log, with how often each appears and the line numbers where it occurs.
Pick, reorder and rejoin columns from delimited text, like cut -f, with quoted CSV fields respected.
Hard-wrap text at a column width while keeping quote, indent and bullet prefixes, or unwrap it back into paragraphs.
Split long text into numbered parts that fit a chat model's limit, each wrapped in a wait-for-the-last-part prompt.
Analyse
Count characters, words, lines, and byte size for any block of text as you type.
Count how often each word or phrase appears in a text, with stop-word filtering, n-grams and CSV export.
Estimate how long a text takes to read or speak aloud and get a ready min-read badge.
Spot easily confused characters like 1, l and I or 0 and O in a password or code, with each character spelled out.
Check whether an SMS fits GSM-7 or needs UCS-2, count its segments and replace the characters that cost extra.
Estimate GPT token counts and API cost for a piece of text.
Style & generate
Turn plain text into bold, italic, script, fraktur, upside-down and other Unicode lookalike styles you can paste anywhere.
Turn a line of text into large ASCII-art lettering, choosing from a range of FIGlet fonts.
Shorten words to numeronyms such as i18n or a11y, and expand them back again.
Search and copy emoji along with their name, Unicode codepoints, and shortcode.
Generate filler paragraphs, sentences, or words of lorem ipsum for mockups and layout work.
Turn an indented list or file paths into a tree diagram, or a tree output back into a list of paths.
Transliterate Latin text to Elder Futhark, Younger Futhark or Anglo-Saxon Futhorc runes and back.
Format books, articles, chapters and web pages as APA, MLA, Chicago and Harvard citations or BibTeX.
Read & speak
Read text aloud with your browser's voices, adjust rate, pitch and volume, and follow the highlighted word.
Read text one word at a time at a set pace, with the focus letter highlighted.
Measure your typing speed in words per minute and your accuracy over a timed passage.
Web & design
66 toolsParse and build URLs, write CSP and security headers, convert Markdown, and pick colours, gradients and shadows.
Web
56— URLs, HTTP headers, web security, HTML, Markdown, SEO, and browser testsURLs
Percent-encode text for safe use in a URL, or decode a percent-encoded string back to plain text.
Break a URL into its parts: scheme, host, port, path, query parameters, and credentials.
Follow every hop in a URL's redirect chain and see the status code and target at each step.
Assemble a URL from its protocol, host, port, path, fragment and a table of query parameters, encoded correctly.
Strip utm_*, fbclid, gclid and other tracking parameters from links, and unwrap Google and Facebook redirect URLs.
Tag a landing-page link with utm_source, utm_medium, utm_campaign and friends without losing its existing parameters.
Create a link that scrolls to and highlights specific text on a page with a Text Fragment URL.
Turn a phrase into a lowercase, hyphenated slug that is safe for URLs, filenames, and IDs.
Recover the original link wrapped inside an Outlook SafeLinks URL.
Decode SharePoint and OneDrive sharing links into the item type, site, path and a readable URL.
HTTP & headers
Browse every HTTP status code with its short name and what it signals.
Look up the MIME type for a file extension, or the extensions tied to a MIME type.
Build a Cache-Control header from directives, or paste one to see what each directive means and what conflicts.
Parse Cookie and Set-Cookie headers into a table of values and attributes and flag common mistakes.
Redact cookies, auth headers, tokens and other secrets from a HAR file in your browser before sharing it.
Pull the browser, engine, operating system, CPU, and device out of a user-agent string.
Combine a username and password into the Base64 value for an HTTP Basic Authorization header.
Send HTTP requests from your browser and inspect the status, timing, headers and formatted body.
Connect to a ws:// or wss:// endpoint, send text, JSON or binary messages and watch a timestamped log.
Security
Build a Content-Security-Policy directive by directive, or paste one to see what it allows and where it is weak.
Generate HSTS, Referrer-Policy, Permissions-Policy and cross-origin headers as nginx, Apache, Caddy, Netlify, Vercel or Express config.
Create an RFC 9116 security.txt file with contact, expiry and policy fields, checked for required values.
Defang or refang URLs, IP addresses and emails for safely sharing threat-intel indicators.
HTML
Shrink HTML by removing comments and collapsing whitespace, while leaving pre, textarea, script and style content untouched.
Edit rich text visually and get the matching HTML source updated as you type.
Indent messy or minified HTML, keeping pre, textarea, script and style contents exactly as they are.
Convert HTML into GitHub-flavoured Markdown with headings, lists, links, images, code blocks and tables.
Extract an HTML table, with colspan and rowspan expanded, as CSV, JSON, Markdown or SQL INSERT statements.
Turn loose HTML into well-formed XHTML and check the result with the browser's XML parser.
Strip Word and Google Docs junk from pasted HTML while keeping headings, lists, links and tables.
Convert CSS selectors to XPath 1.0 expressions and translate XPath back to CSS where it maps.
SEO
Fill in a short form to generate the Open Graph and Twitter Card meta tags for a page.
Build a robots.txt with crawler groups, sitemaps and AI-crawler blocking, and test whether a URL is allowed for a bot.
Create a PWA manifest.json with icons, colours and shortcuts, plus the head tags, checked for installability.
Build share links for X, Facebook, LinkedIn, Reddit, Hacker News, Telegram, WhatsApp, Bluesky, Mastodon, email and Pinterest.
Build a correctly encoded mailto link and HTML snippet from recipients, subject and body, or parse an existing one.
Reduce an email address to a canonical form — lowercasing, dropping dots and +tags — so duplicates line up.
Parse a raw email or .eml file into decoded headers, delivery hops, SPF/DKIM/DMARC results, MIME parts, bodies and attachments.
Read a bounce or DSN message to see which recipient failed, the SMTP status code and what it means.
Turn a DMARC aggregate report (XML or .xml.gz) into pass rates and a filterable table of sending sources.
Browser & device
Read back what the browser exposes about your screen, viewport, platform, and capabilities.
Check every key on your keyboard with a live on-screen layout that lights up held keys, remembers tested ones and measures key rollover.
Press any key to see its JavaScript key, code, keyCode, location, and active modifiers.
Hunt for dead or stuck pixels with fullscreen solid colours, a gradient and a checkerboard, and see your screen's resolution, pixel ratio and refresh rate.
A stopwatch with laps, a countdown timer that beeps when done, and a configurable Pomodoro timer that stays accurate in background tabs.
Markdown
Convert GitHub-flavoured Markdown to HTML and preview the result in a sandboxed frame.
Strip Markdown formatting down to readable plain text, keeping link text, list bullets, code and table cells.
Turn the headings of a Markdown document into a nested table of contents with GitHub-compatible anchor links.
Build a GitHub-flavoured Markdown table in an editable grid or from pasted CSV, TSV, JSON or Markdown, with aligned columns.
Re-pad every table in a Markdown document so its columns line up, leaving the rest of the text untouched.
Write Markdown with a live preview, formatting toolbar, word count and export to .md or standalone .html.
Convert between GitHub Markdown, Slack mrkdwn, Jira wiki markup, Discord, Telegram MarkdownV2 and BBCode.
Paste rich text from web pages, Google Docs, Word or spreadsheets and get clean Markdown.
Convert Markdown tables to CSV, JSON, SQL INSERT statements, HTML or YAML.
Generate sample Markdown documents with headings, nested lists, tables, code blocks, quotes, links, images and task lists.
Convert an EPUB e-book to a single Markdown file in your browser, chapters in reading order.
Design
10— Colours, palettes, gradients, shadows, SVG, and code highlightingColor
Convert a CSS colour between hex, RGB, HSL, HWB, OKLCH, OKLAB and the nearest named colour.
Turn one colour into harmonies and a 50–950 OKLCH tint and shade scale, exported as CSS variables or Tailwind config.
Check the WCAG contrast ratio between a text and background colour and see which AA and AAA levels it passes.
CSS
Build linear, radial and conic CSS gradients with colour stops, an interpolation space and a live preview.
Stack box-shadow layers with offset, blur, spread, colour and inset, preview them on a card and copy the CSS.
Minify CSS safely, keeping strings, url() values and custom properties intact, or beautify it back into readable rules.
SVG & code
Preview SVG safely, inspect its size and viewBox, minify it, and export it as a PNG at any scale.
Syntax-highlight code in common languages and themes with Shiki and copy the result as an HTML snippet.
Turn an image into a data URI, CSS background, img tag, SVG wrapper or box-shadow pixel art.
Dev & ops
85 toolsRegex, SQL and Git helpers, Docker and Kubernetes generators, nginx and systemd config, firewalls and subnets.
Development
24— Git, regex, semver, SQL, curl, and project filesGit
Build a Conventional Commits message with lint hints and a ready-to-run git commit command.
Step-by-step git commands to undo common mistakes, from a commit on the wrong branch to a leaked file in history.
Pick languages, frameworks, editors and operating systems to build one combined, de-duplicated .gitignore file.
Generate a .gitattributes file for line endings, binary files, Git LFS, GitHub linguist, export-ignore and language-aware diffs.
Code & HTTP
Try a regular expression against sample text and watch every match and capture group highlight as you type.
Validate, compare, sort and bump semantic versions, and check whether a version satisfies an npm range.
Turn a curl command into JavaScript fetch, Python requests, Go net/http or HTTPie code.
Pick a random TCP port from the ephemeral range, clear of the well-known ports below 1024.
Open a Minecraft plugin or mod .jar in the browser to browse its files, preview them, and extract individual entries.
Split a command line into program, flags and arguments, edit or reorder them, and get it back quoted for Bash, PowerShell or cmd.
Build ANSI colour and style escape codes with a live terminal preview, or preview and strip the codes from coloured text.
Paste a JavaScript, Java, .NET, Python or Go stack trace to see its frames, chained exceptions and your own code highlighted.
Test glob patterns (*, **, braces, extglobs, negation) against a list of paths and see the RegExp they compile to.
Hide JavaScript strings behind escapes or wrap a script in a Base64 or ROT13 loader, and reveal it again.
Compare the speed of JavaScript snippets in Web Workers, with ops/sec, error margin and a chart.
SQL & databases
Reformat a SQL query with clean indentation and consistent keyword casing across common dialects.
Strip comments and collapse whitespace in SQL without touching strings, quoted identifiers, dollar-quoted bodies or optimizer hints.
Paste a list of values and get a quoted, de-duplicated SQL IN clause, chunked for Oracle's 1000-item limit, or a VALUES, UNION ALL or ANY(ARRAY) alternative.
Build or parse database connection strings for PostgreSQL, MySQL, MongoDB, Redis, SQL Server and SQLite with safely encoded credentials.
Build a CREATE TABLE statement with keys, defaults, checks and indexes for PostgreSQL, MySQL, SQLite, SQL Server or Oracle.
Generate CREATE DATABASE, a login user and read-only, read-write or owner grants, plus the matching revoke and drop scripts.
Fill ?, $1, :name, @name or %s placeholders with values to get runnable SQL from a log, or turn literals back into parameters.
DevOps
36— Docker, Kubernetes, CI, web servers, Linux config, and firewallsDocker
Paste a docker run command and get the equivalent docker-compose service definition.
Paste a docker-compose file and get a ready-to-run docker run command for each service, with anything that cannot be converted listed.
Check a docker-compose file for YAML errors and Compose Spec problems such as unknown keys, bad ports, missing services, undeclared volumes and clashing host ports.
Extract every variable from a docker-compose file into a .env template with defaults filled in, and see which ones your .env leaves unset.
Generate OCI image annotations as a Dockerfile LABEL block, docker build --label flags and a docker/metadata-action snippet.
Rebuild the docker run command for an existing container from its docker inspect JSON.
Normalise a docker-compose file by switching ports, volumes, environment and depends_on between short and long syntax.
Kubernetes & CI
Fill in a form to build a Deployment, Service, Ingress and HorizontalPodAutoscaler as one YAML file with consistent labels.
Build a ServiceAccount with a Role or ClusterRole and its binding, with risky-rule warnings and kubectl auth can-i checks.
Generate a least-privilege GitHub Actions CI workflow for Node, Python, Go, Rust or a Docker image pushed to GHCR.
Generate Traefik v3 docker compose labels for routing, TLS and middlewares, plus a minimal Traefik service.
Build a k6 load-test script from a list of requests, checks, a load profile and pass/fail thresholds.
Convert a docker-compose file into Kubernetes Deployments, Services, ConfigMaps, Secrets and PersistentVolumeClaims.
Turn one or more docker run commands into Kubernetes Deployment, Service, ConfigMap and PVC manifests.
Servers & Linux
Generate an nginx server block for a static site, SPA, reverse proxy or PHP-FPM app, with HTTPS, redirects and security headers.
Generate an Apache .htaccess file with HTTPS and www redirects, error pages, compression, caching, password protection, CORS and IP blocking.
Fill in a form to build a hardened systemd service file, an optional timer, and the commands to install them.
Assemble a cron expression from plain-language options and read back exactly when it will run.
List the next run times of a cron expression in any time zone and in UTC, with a plain-English description.
Create a logrotate config for your app's logs with rotation, compression, file mode and a postrotate script.
Build an aligned /etc/fstab from disks, swap, NFS, CIFS and tmpfs mounts, with checks for common mistakes.
Toggle read, write, and execute bits for owner, group, and others to get the matching octal mode and chmod command.
Build an ~/.ssh/config with host aliases, jump hosts, port forwards and shared defaults, ready to save.
Assemble a safely quoted rsync command from toggles, with each flag explained and a dry run on by default.
Build sed substitute, delete, print, insert and append commands with a live preview and GNU vs macOS differences.
Get the shutdown, reboot or cancel command for Linux, systemd, macOS and Windows, now, after a delay or at a set time.
Generate restic environment variables and backup, restore, mount, forget and check commands for local, SFTP, S3, B2 or REST repositories.
Re-indent an nginx config and catch missing semicolons, unbalanced braces and duplicate listen or server_name.
Firewall & capture
Turn a list of firewall rules and default policies into ufw commands, an iptables-save file and an nftables ruleset.
Build a tcpdump command with a BPF filter from host, net, port and protocol rules, explained in plain English.
Build an nmap command from scan type, ports, timing, scripts and output options, with root-only options marked.
Build firewall-cmd commands for zones, services, ports, rich rules, masquerading and port forwarding.
Podman
Network
25— IP and subnet maths, MAC addresses, DNS records, and VPN configIP & subnets
See an IPv4 address written as decimal, hexadecimal, binary, and its IPv6-mapped form.
Break an IPv4 CIDR block down into its network and broadcast address, usable host range, mask, and size.
Enter the first and last address of a range and get the smallest CIDR block that covers it.
Rewrite any IPv6 address in compressed, expanded, binary, hex, decimal and reverse-DNS form, and see what kind of address it is.
Get the first and last address and size of an IPv6 prefix, and split it into smaller subnets.
Roll a random IPv6 unique local address prefix (fd00::/8) for private networks, following RFC 4193.
Turn an IPv4 or IPv6 CIDR block into its address range, or a range back into the fewest CIDR blocks.
Check which CIDR blocks contain each IP address in a list, and spot overlapping blocks.
Split an IPv4 or IPv6 network into a number of equal subnets or into subnets of a chosen prefix length.
Convert decimal, hex or binary integers to IPv4 and IPv6 addresses, and addresses back to integers.
Subtract excluded ranges from allowed ones and get the fewest CIDR blocks, such as WireGuard AllowedIPs without your LAN.
Divide and join IPv4 subnets in a clickable tree, add notes, and share or export the plan.
MAC
Convert a MAC address between colon, dash, Cisco dot and bare formats, and get its EUI-64 and IPv6 link-local address.
Generate one or many random MAC addresses with a fixed prefix, case, and separator of your choosing.
Look up the hardware vendor registered to a MAC address or OUI prefix.
DNS records
Build SPF and DMARC TXT records for your domain, with a lookup counter and a ready-to-paste zone file line.
Generate a DKIM key pair in your browser or paste an existing public key, and get the selector._domainkey TXT record to publish.
Choose which certificate authorities may issue certificates for your domain and get the CAA records to publish.
Create an MTA-STS policy file plus the _mta-sts and TLS-RPT TXT records that make mail servers require TLS for your domain.
Turn an IP address into its in-addr.arpa or ip6.arpa name and PTR record, or an arpa name back into an address.
Build the default._bimi TXT record for your brand logo and VMC, and check your DMARC policy qualifies.
DHCP, VoIP & email
Encode wireless controller IPs for Cisco, UniFi and Aruba access points as DHCP option 43 hex, with server config lines.
Compute or verify a SIP or HTTP Digest Authorization response (MD5 or SHA-256), with every hashing step shown.
Decode the obfuscated X-VR-SPAMCAUSE header OVH adds to mail to see why it was flagged as spam.
Security
41 toolsHashes, HMACs, keys and certificates, passwords and JWTs, computed in your browser so secrets stay on your machine.
Crypto & Security
41— Hashing, encryption, keys and certificates, passwords, tokens, and validatorsHashing
Run text through MD5, SHA-1, SHA-256, SHA-3 and other digests, with each result shown in several encodings at once.
Compute the MD5, SHA-1, SHA-256, SHA-384 and SHA-512 checksums of a file and verify it against an expected hash.
Compute an HMAC signature from a message and secret key using the hash function of your choice.
Compute CRC-8, CRC-16, CRC-32, CRC-32C and Adler-32 checksums of text or raw hex bytes.
Hash a string with bcrypt at a work factor you choose, or test a string against an existing bcrypt hash.
Derive keys with PBKDF2 or HKDF using SHA-1, SHA-256, SHA-384 or SHA-512, with OWASP's recommended PBKDF2 iteration counts.
Encryption
Encrypt or decrypt a message with a passphrase using AES, TripleDES, Rabbit, or RC4.
Encrypt, decrypt, sign and verify text with RSA keys using RSA-OAEP, PKCS#1 v1.5 or PSS with SHA-256.
Split a secret into N shares so that any K of them can rebuild it, and combine shares back into the secret.
Mask the middle of a secret, IBAN, or token so it can be shared and recognised without exposing the whole value.
Encrypt and decrypt Ansible Vault secrets (format 1.1 and 1.2 with a vault ID) in your browser, with the HMAC checked before decrypting.
Encrypt and decrypt Jasypt values (PBEWithMD5AndDES or PBEWITHHMACSHA512ANDAES_256) for Spring Boot ENC(...) properties.
Keys & certificates
Generate a fresh RSA public and private key pair in PEM format at the key size you pick.
Generate ECDSA (P-256, P-384, P-521) or Ed25519 key pairs as PEM, JWK and OpenSSH public keys.
Create a certificate signing request and RSA private key from subject fields and alternative names.
Create a self-signed X.509 certificate and RSA private key for local development and testing.
Decode a PEM certificate or CSR to see its subject, issuer, validity, names, key and fingerprints.
Inspect the digital signatures embedded in a PDF and check whether the file changed after it was signed.
Convert certificates between PEM and DER, unpack PKCS#7 (.p7b) and PKCS#12 (.p12/.pfx) files, and build a .p12 from a certificate and key.
Passwords & secrets
Build a random token from the character sets you enable — lowercase, uppercase, digits, symbols — at any length.
Make diceware-style passphrases from the 2048-word BIP39 list, with its entropy in bits and a plain-language strength estimate.
Estimate how long a password would take to crack and see which choices are weakening it.
Turn usernames and passwords into bcrypt, APR1-MD5 or SHA-1 lines for Apache and nginx basic-auth password files, hashed in your browser.
Generate a Django SECRET_KEY plus secret keys for Rails, Laravel and Flask.
Derive the 256-bit WPA/WPA2 pre-shared key from a Wi-Fi network name and passphrase.
Generate live TOTP and HOTP codes from a Base32 secret, with a scannable QR code for authenticator apps.
Generate a BIP39 recovery phrase from random entropy, or paste a phrase to recover the entropy behind it. Multiple wordlists supported.
Tokens
Split a JSON Web Token into its header, payload, and signature and read the decoded claims.
Build and sign a JSON Web Token with an HMAC secret or an RSA, EC or Ed25519 key, then verify it, all in your browser.
Decode a SAMLRequest or SAMLResponse from base64, DEFLATE or a redirect URL into readable XML, key fields, attributes and the signing certificate.
Validators
Check a card, IMEI or account number against the Luhn mod-10 rule, see the doubling steps and work out a missing check digit.
Check a card number's brand, length and Luhn checksum and format it the way it is printed.
Validate an IBAN's length and mod-97 checksum and break it into country, check digits, bank code and account number.
Verify the check digit of an ISBN-10 or ISBN-13 and convert between the two forms.
Check the format and check digits of EU and UK VAT numbers offline.
Classic ciphers
Shift letters with a Caesar, ROT13 or ROT47 cipher, or crack one by ranking all 25 shifts against English letter frequencies.
Encrypt or decrypt with the Vigenère, Beaufort or autokey cipher and guess an unknown key with Kasiski and index-of-coincidence analysis.
Encrypt and decrypt with Atbash, rail fence, affine, Playfair and Bacon ciphers, with the rail zig-zag and Playfair key square shown.
XOR text, hex or base64 data with a repeating key, and brute-force single-byte XOR ranked by how much the result looks like English.
Generate & media
43 toolsUUIDs and other IDs, seeded mock data, QR codes and barcodes, and image tools that never upload a file.
Generators
18— IDs, random picks, and fake dataIDs
Create RFC 4122 UUIDs (v1, v3, v4, v5) singly or in bulk, in several output formats.
Create ULIDs, the time-sortable unique identifier, one at a time or in bulk, as plain text or JSON.
Generate short, URL-safe random IDs with your choice of length and alphabet, and see how long they last before a collision is likely.
Inspect any UUID to see its version, variant and embedded timestamp or MAC address, and convert it to other formats.
Read the creation time, random value and counter inside a MongoDB ObjectId, or build one from a date for range queries.
Turn Twitter, Discord, Instagram or Mastodon snowflake IDs into timestamps and worker fields, or find the ID for a date.
Random
Draw unbiased random integers or decimals from any range, with unique and sorted options plus quick dice rolls and coin flips.
Generate random numeric PINs of 4 to 12 digits, optionally skipping repeated digits, simple sequences and the most common PINs.
Flip one or more fair coins and keep a running tally of heads and tails with a history of every flip.
Roll dice from standard notation like 2d6+3, 4d6kh3 or d% and see every die and the total.
Pick random winners from a list, shuffle it, or split it into even teams.
Spin a wheel of names or options, with optional weights, to pick a random winner.
Shuffle a standard deck of playing cards, draw cards or deal hands to several players.
Generate random, pastel, vivid, dark or harmonious colour palettes in OKLCH, lock favourites and export them as CSS variables or JSON.
Generate batches of adjective-noun usernames with separators, case styles, number suffixes and Discord, GitHub or X naming rules.
Fake data
Generate realistic fake rows (names, emails, dates, IPs and more) as JSON, CSV, SQL INSERT or NDJSON, reproducible from a seed.
Create dummy files of an exact size, or valid PNG, JPEG, PDF and ZIP files, for testing uploads and size limits.
Turn any text or SHA-256 hash into a GitHub-style, pixel, ring or beam avatar and export it as SVG or PNG.
Barcode & QR
8— Read and generate barcodes, QR codes, and GTINsQR codes
Turn a URL or any text into a QR code, set the error-correction level, and download it.
Read a QR code from an image or your camera and work out what kind of content it carries.
Create a QR code that joins a phone to your Wi-Fi network in one scan.
Enter contact details and get a vCard QR code that scans straight into a phone’s address book.
Build a SEPA credit-transfer QR code (GiroCode / EPC069-12) that a banking app can scan to prefill a payment.
Barcodes
Generate 1D and 2D barcodes — Code 128, EAN, UPC, ITF, Data Matrix, PDF417, Aztec and more — and save them as PNG or SVG.
Read a barcode or QR code from an uploaded image or a live camera feed.
Check the GS1 check digit of a GTIN-8, GTIN-12, GTIN-13 (EAN-13), or GTIN-14 barcode number.
Images & Media
17— Image editing and conversion, plus camera, mic, and audio toolsImages
Turn PNG, JPEG, WebP, GIF, BMP, SVG or AVIF images into PNG, JPEG, WebP or AVIF in your browser, with a quality slider and the size saved per file.
Scale images by percentage or to exact pixels, with contain, cover-crop or stretch fitting and sharp step-down downscaling, all without leaving your browser.
Crop an image by dragging a box or typing exact pixels, with aspect-ratio presets, rotation and flipping, all in your browser.
Adjust brightness, contrast, saturation, hue, blur and more with a live before/after preview, then download the filtered image.
Compare two images with a before/after slider, side by side, or a pixel difference map that shows exactly what changed.
See the camera, date and GPS location hidden in a JPEG or PNG, then strip that metadata byte-for-byte without re-encoding the picture.
Make a full favicon set from an image or a letter or emoji, with PNGs from 16 to 512 px, a multi-size favicon.ico, and the HTML and manifest to paste.
Pick exact pixel colours from an image with a magnifier and get its dominant colour palette as hex, RGB and HSL.
Turn an image into plain-text or coloured ASCII art with adjustable width and character sets.
Build a placeholder image at any size — pick colours, a label, and a pattern, then export it as SVG, PNG, JPEG, or WebP with ready-made HTML, CSS, and Markdown snippets.
Read EXIF, GPS, camera, XMP, colour profile and JPEG quality from a photo without changing it.
Add a text or logo watermark to one or many images, placed or tiled, then download.
Audio & video
Check your camera in the browser and see the resolution, frame rate and capabilities it actually delivers, then take a snapshot.
Test your microphone with a live level meter, waveform and spectrum, and record a short clip to play back.
Play a test tone, frequency sweep or white or pink noise at any pitch, with a note picker and left/right channel test.
Record your screen, a window or a tab with optional microphone audio, then preview and download the video, all in your browser.
Record video with sound from your webcam or take photos, then download them.
Calculators & reference
102 toolsDate maths, electronics, money and infrastructure calculators, a Discord toolkit, and searchable cheatsheets.
Calculators
42— Maths, dates, money, electronics, and infrastructure calculatorsMath
Type a mathematical expression and get the result, with support for functions like sqrt, sin, and log.
Work out a percent of a number, what percent one number is of another, and percent change.
Reduce a width and height to its aspect ratio, or resize while keeping the ratio locked.
Apply AND, OR, XOR, NOT and shifts to two integers at 8 to 64 bits, with a bit-by-bit view.
Turn decimals into the simplest fraction or nearest inch fraction, fractions into exact repeating decimals, and inches into millimetres.
Convert math between expressions, LaTeX, MathML, AsciiMath and Unicode text with a live preview.
Plot several functions of x with pan, zoom, degrees or radians and a tracing cursor.
Date & time
Count the years, months, days and business days between two dates, with totals down to the second.
Add or subtract years, months, weeks, days, hours or business days from a date and get the weekday and ISO week.
Add and subtract durations like 1h 30m or 01:20:15, and find the time between two clock times.
Find the ISO 8601 and US week number, day of year and quarter for any date, or list the days of an ISO week.
Compare up to six time zones hour by hour and find the times that fall inside everyone's working hours.
Find the time remaining and finish time of a copy, download or batch job from its progress and rate.
Find the weekday a date falls on across a range of years, and the next year it lands on a given weekday.
Calendars & alarms
Read an .ics calendar file as a table of events, with time zones and repeating events expanded, and export it as CSV or JSON.
Create an .ics calendar event with time zone, attendees, reminder and repeat rule, plus Add to Google Calendar and Outlook links.
Merge several .ics calendar files into one calendar, removing duplicate events and time zones.
Convert a date between the Gregorian, Islamic, Hebrew, Persian, Chinese and other calendars, Julian Day, Unix time and Excel serial numbers.
Set browser alarms for a date and time, chosen weekdays or a cron schedule in any time zone, with sound and notifications while the page is open.
Money
Work out the tip and total on a bill, and split it evenly between any number of people.
Calculate the monthly payment on a loan and see the full principal/interest schedule.
Project how savings grow with compound interest and regular contributions, year by year.
Work out the electricity use and running cost of one or more devices per day, month and year.
Electronics
Enter any two of voltage, current, resistance and power to get the other two, with SI prefixes like 4.7k and 20m.
Work out a divider's output voltage, current and resistor power, or find R1 for a target voltage with the nearest E12, E24 and E96 values.
Find the series resistor for one or more LEDs, rounded up to a standard E-series value, with its power rating and actual current.
Get an RC circuit's time constant, charge curve and cutoff frequency, find R for a target cutoff, or an LC circuit's resonant frequency.
Decode a resistor's color bands into its resistance and tolerance, or the reverse — type a value to get the bands.
Estimate how long a battery lasts from its capacity and the device's average or sleep and active current, and size series and parallel packs.
Infrastructure
Work out usable capacity, efficiency and fault tolerance for RAID 0, 1, 5, 6, 10, 50 and 60 arrays.
Turn an uptime percentage into allowed downtime per day, week, month, quarter and year, or downtime back into uptime.
Work out how long a file takes to transfer at a given connection speed, or the speed needed to finish in time.
See how much space a TB or GB drive really shows in your OS, with filesystem overhead and a table of common sizes.
Calculate raw and usable ZFS pool capacity for stripe, mirror and RAIDZ vdev layouts, with slop space and fault tolerance.
Estimate mean time to data loss and the chance of losing data for RAID 5, 6, 10 and RAIDZ arrays.
Convert DNS and cache TTLs between seconds and human durations and see when they expire.
Health & travel
Calculate Body Mass Index from your weight and height, in metric or imperial units.
Solve for time, pace, or distance from the other two, with quick presets for common race distances.
Calculate the great-circle distance and initial bearing between two latitude/longitude points.
Estimate BMR, daily calorie needs, ideal weight and US Navy body fat in metric or imperial units.
Discord
10— Timestamps, permissions, embeds, webhooks, and message formatting for DiscordMessages
Type a Discord message and see its bold, spoilers, quotes, lists, code blocks, mentions and timestamps rendered as you go, with a character count against the send limit.
Color parts of your text with Discord's ANSI palette and copy a ready-made ansi code block that shows them in chat.
Design a webhook message with up to ten rich embeds, see a live preview, and edit the JSON payload directly with Discord's size limits checked as you type.
Turn a date into Discord timestamp tags with a preview of each style, or read the date behind tags in a message.
Split Discord message links into server, channel and message IDs with the time each was created, or put a link back together from IDs.
Bots & webhooks
Post a JSON message to a Discord webhook, or look up and delete the webhook, with requests going straight from your browser to Discord and the URL never stored.
Build the OAuth2 authorize link that installs your bot or app, with scopes, permissions and redirect options checked as you go.
Tick Discord permission flags to build the integer for a bot or role, or paste an integer to see which flags it grants.
See the user ID, account creation date and issue time hidden in a Discord token, decoded entirely in your browser.
Cheatsheets
50— Quick-reference guides for languages, shells, DevOps, and webLanguages
A searchable quick reference for modern JavaScript — array, string, object, and async/Promise built-ins.
A searchable quick reference for TypeScript — basic types, interfaces, generics, utility types, and conditional/mapped types.
A searchable quick reference for Python — slicing, comprehensions, f-strings, functions, control flow, and type hints.
A searchable quick reference for Go — variables, slices & maps, structs & interfaces, goroutines/channels, and errors.
A searchable quick reference for Rust — ownership & borrowing, pattern matching, iterators, traits, and Cargo.
A searchable quick reference for SQL — queries, joins, aggregation, window functions, DDL, and CTEs.
Shell & CLI
A searchable quick reference for Bash — redirection, variable expansion, globs, tests, control flow, and process management.
A searchable quick reference for PowerShell — navigation, the object pipeline, common cmdlets, strings, files, processes, remoting, and bash equivalents.
A searchable quick reference for the find command — matching by name, type, size, and time, then acting on the results.
A searchable quick reference for grep and ripgrep (rg) — matching, context lines, and restricting search by file type.
A searchable quick reference for sed and awk — substitution, line selection, fields, and quick filters/aggregates.
A searchable quick reference for jq — filters, transforms, reductions, and string/regex helpers for JSON on the command line.
A searchable quick reference for curl — methods, request bodies, headers, auth, output options, and redirects.
A searchable quick reference for SSH, SCP, and rsync — connecting, keys, port forwarding, file transfer, and ~/.ssh/config.
A searchable quick reference for GNU Make — rules, variables, automatic variables, functions, and CLI flags.
A searchable quick reference for tmux — sessions, windows, panes, copy mode, and config reloading.
A searchable quick reference for Vim/Neovim — modes, motions, editing, search & replace, windows, registers, and macros.
A searchable quick reference for Unix permissions — octal and symbolic chmod modes, special bits, umask, chown and find -perm.
A searchable quick reference for the GNU nano editor — shortcuts, search and replace, cut and paste, buffers and nanorc options.
A searchable quick reference for GNU Screen — sessions, Ctrl-a key bindings, windows, splits, copy mode, logging and .screenrc.
A searchable quick reference for the Zellij terminal multiplexer — modes, default keybindings, CLI commands, layouts and config.
DevOps
A searchable quick reference for Git — everyday commands, branching, undoing mistakes, stashing, remotes, and history search.
A searchable quick reference for .gitignore pattern syntax, common entries per stack, and related git commands.
A searchable quick reference for Conventional Commits message types and Semantic Versioning (MAJOR.MINOR.PATCH) rules.
A searchable quick reference for the Docker CLI — running and managing containers, images, Compose, volumes, cleanup, and Dockerfile instructions.
A searchable quick reference for Docker Compose v2 — the docker compose CLI plus compose file keys for builds, ports, volumes, healthchecks, profiles, secrets, and more.
A searchable quick reference for Dockerfiles — every instruction, multi-stage builds, BuildKit cache and secret mounts, heredocs, .dockerignore, and best practices.
A searchable quick reference for kubectl — contexts, get/describe, logs & exec, applying manifests, and debugging.
A searchable quick reference for nginx — CLI, server and location matching, proxy_pass, headers, TLS, redirects, rewrites, gzip, rate limiting, upstreams, and variables.
A searchable quick reference for systemctl and journalctl — controlling services, inspecting units, and reading logs.
A searchable quick reference for well-known and commonly-used TCP/UDP ports — web, mail, infra, databases, and dev servers.
A searchable quick reference for Docker Swarm — nodes, services, stacks, secrets, overlay networks and rolling updates.
A searchable quick reference for ZFS — zpool and zfs commands for pools, datasets, properties, snapshots, send/receive and quotas.
Web
A searchable quick reference for CSS selectors — combinators, attribute selectors, pseudo-classes/elements, and specificity.
A searchable quick reference for CSS color formats and functions — hex, rgb/hsl/oklch, keywords, gradients, and filters.
A searchable quick reference for CSS Flexbox and Grid — container and item properties, plus common layout recipes.
A searchable quick reference for HTTP methods, safe/idempotent/cacheable semantics, status code ranges, and common headers.
A searchable quick reference for Markdown — text formatting, lists, links, and GitHub Flavored Markdown extensions.
A searchable quick reference for ANSI/VT100 escape codes — terminal colors, text styles, cursor movement, and clearing.
Patterns & formats
A quick reference for JavaScript regular-expression syntax: tokens, character classes, groups, flags, and lookarounds.
A searchable collection of ready-to-use regular expressions for emails, URLs, IP addresses, UUIDs, dates, phone numbers, postal codes, passwords, and more.
A searchable quick reference for glob syntax across the shell, .gitignore-style files, and JS tooling (picomatch/fast-glob).
A searchable quick reference for RFC 9535 JSONPath — selectors, descendants, slices, filters, and functions, with notes on where older implementations differ.
A searchable quick reference for XPath — axes, node tests, predicates, functions, common recipes, and CSS selector equivalents.
A searchable quick reference mapping date/time format tokens across strftime, date-fns/Moment, and Go's reference layout.
Codes & standards
T568A and T568B pin colours, straight vs crossover cables, gigabit pairs and PoE pin usage for RJ45 Ethernet.
Search every ISO 3166-1 country by name, alpha-2, alpha-3 or numeric code, with its flag emoji.
Search all ISO 639-1 two-letter language codes with their ISO 639-2 three-letter equivalents.
Check whether code under one open-source license can be included in a project under another, from MIT to AGPL-3.0.
Map Active Directory LDAP attribute names to the field labels in Active Directory Users and Computers, plus userAccountControl flags.